To establish the role of heavy marijuana use in the psychosocial adaptation of adolescents, young adults, and adults through: a) follow-up evaluation of subjects who were part of a previous project on adolescent marijuana abusers; b) comparing that group with a new group of long term users who are now young adults or adults. To gather data through combining three research instruments: a structured questionnaire prepared in concert with other groups studying the psychosocial consequences of heavy and long term marijuana use; psychological tests including the WAIS, Rorschach, and MMPI; and, unstructured psychodynamic interviews relying on trend of associations, dreams, omissions, transference, and challenging of defense mechanisms. Data analysis will consist of 3 phases: (1) the establishment of the principal psychodynamic patterns related to drug use that characterize each cohort; (2) a rank ordering of importance within cohorts of these themes; and (3) within and between groups, comparisons of the frequency and relative importance of each psychodynamic theme.